Hello everyone,
I've posted this in the gtx 1080 feedback thread and someone suggested I create my own thread as it might get more attention.
So here goes.
I just upgraded to a PNY GTX 1080 FE and unfortunately, even though the performance is great, all my games and videos on youtube or netflix now stutter, sometimes with crackling sound.
As I already had some experience with crackling sound on an old configuration of mine, I decided to check the DPC Latency with DPCLat (I am on Windows 7 x64 SP1). To my surprise, I found out that the DPC Latency is around 350-400us when the PC is idle and it is around 900us with spikes up to 1500us when in game or netflix. The stutter happens usually when the spikes occur. I checked the gpu usage and its temperature and all is well (99% usage, 85C peak temperature as per design), with no sign of throttling.
I used to have a GTX Titan X and never had any trouble at all, the DPC latency being around 20-25us.
Below is the list of the things I've tried so far.
If I disable the GTX 1080 in the device manager, the DPC latency goes back to 20-25us. I can watch a video on youtube or Netflix and the DPC doesn't change and I don't experience stutter or crackling sound.
As soon as I enable the graphics card driver again, the DPC goes back to 350-400us, and it's a stutter fest when I watch videos or play games.
I ran LatencyMon to confirm that the cause of the high DPC Latency was caused by the graphics card. The tool reports that nvlddmkm.sys is causing the high dpc latency and it also reports that it is called all the times by the OS.
For a sanity check, I installed the Titan X back with the same drivers (368.39), and I can confirm I am not crazy (at least not in this department ;)) as all is well with a low dpc and not stutter.
It seems that if I set the power management mode to Prefer Maximum performance and let chrome or skype run in background (they force the graphics card to run at full speed due to their hardware acceleration), the DPC latency goes down to 30us. However, the DPC remains high in game with a 800-900us average. The stuttering has dialed down a notch and the sound doesn't crack. Still, it doesn't feel as smooth as it used to on the GTX Titan X.
Disabling Hyperthreading on my computer doesn't help a bit.
All C-States are disabled on the CPU, as well as the speedstep feature. I disabled the network controller, the usb 2.0 & 3.0 controllers, the audio one too, basically I stripped everything down to have the bare minimum and yet the problem persists.
Forced the p-state to 0 (thanks nvidia inspector) in order to get the gpu to boost at full frequency reduces the DPC latency but doesn't fix the stuttering.
I have made a couple of screenshots to show the DPC when I disable and enable the driver when the pc is idle: http://imgur.com/a/eh2wa
My computer spec is as follow:
* Intel Core i7 6700k
* Gigabyte z170x gaming 5
* 4x4GB Kingston DDR4 3000Mhz CAS 15
* PNY GTX 1080 FE
* Asus Xonar DX
* Samsung 850Pro 512GB
* AOC G2460PG G-Sync
* EVGA 220-G2-0850-XR 80 PLUS GOLD 850W
For all this, I have a strong feeling this might be due to the way the driver handles nvidia boost 3.0 in order to match the temp, voltage & frequency curves closely to have a more accurate range of frequencies. Just a guess I know but I would imagine that this needs some kind of permanent monitoring system that is likely done on the software part (I doubt it's done on the hardware side).
Does anyone has the same issue? If yes, can at least someone warn Nvidia so that can have a look at it?
Thanks!

Hello everyone,
I've posted this in the gtx 1080 feedback thread and someone suggested I create my own thread as it might get more attention.

So here goes.

I just upgraded to a PNY GTX 1080 FE and unfortunately, even though the performance is great, all my games and videos on youtube or netflix now stutter, sometimes with crackling sound.

As I already had some experience with crackling sound on an old configuration of mine, I decided to check the DPC Latency with DPCLat (I am on Windows 7 x64 SP1). To my surprise, I found out that the DPC Latency is around 350-400us when the PC is idle and it is around 900us with spikes up to 1500us when in game or netflix. The stutter happens usually when the spikes occur. I checked the gpu usage and its temperature and all is well (99% usage, 85C peak temperature as per design), with no sign of throttling.

I used to have a GTX Titan X and never had any trouble at all, the DPC latency being around 20-25us.

Below is the list of the things I've tried so far.

If I disable the GTX 1080 in the device manager, the DPC latency goes back to 20-25us. I can watch a video on youtube or Netflix and the DPC doesn't change and I don't experience stutter or crackling sound.
As soon as I enable the graphics card driver again, the DPC goes back to 350-400us, and it's a stutter fest when I watch videos or play games.

I ran LatencyMon to confirm that the cause of the high DPC Latency was caused by the graphics card. The tool reports that nvlddmkm.sys is causing the high dpc latency and it also reports that it is called all the times by the OS.

For a sanity check, I installed the Titan X back with the same drivers (368.39), and I can confirm I am not crazy (at least not in this department ;)) as all is well with a low dpc and not stutter.

It seems that if I set the power management mode to Prefer Maximum performance and let chrome or skype run in background (they force the graphics card to run at full speed due to their hardware acceleration), the DPC latency goes down to 30us. However, the DPC remains high in game with a 800-900us average. The stuttering has dialed down a notch and the sound doesn't crack. Still, it doesn't feel as smooth as it used to on the GTX Titan X.

Disabling Hyperthreading on my computer doesn't help a bit.

All C-States are disabled on the CPU, as well as the speedstep feature. I disabled the network controller, the usb 2.0 & 3.0 controllers, the audio one too, basically I stripped everything down to have the bare minimum and yet the problem persists.

Forced the p-state to 0 (thanks nvidia inspector) in order to get the gpu to boost at full frequency reduces the DPC latency but doesn't fix the stuttering.

I have made a couple of screenshots to show the DPC when I disable and enable the driver when the pc is idle: http://imgur.com/a/eh2wa

For all this, I have a strong feeling this might be due to the way the driver handles nvidia boost 3.0 in order to match the temp, voltage & frequency curves closely to have a more accurate range of frequencies. Just a guess I know but I would imagine that this needs some kind of permanent monitoring system that is likely done on the software part (I doubt it's done on the hardware side).

Does anyone has the same issue? If yes, can at least someone warn Nvidia so that can have a look at it?
Thanks!

My DPC is like 500-700 higher if the card is at idle clocks or full load. If it's high clocks and low load
like 10-60% the latency is below 50 (like it was before with my 670). Playing Witcher 3 spikes I have above 1000us which is not good.

My DPC is like 500-700 higher if the card is at idle clocks or full load. If it's high clocks and low load
like 10-60% the latency is below 50 (like it was before with my 670). Playing Witcher 3 spikes I have above 1000us which is not good.

Hello,
Same boat here,
I come from a titan X and my latency was 20-25us before (at idle). The only thing i changed in my system is my new GTX 1080 (MSI gaming) as i was already using the last drivers and now my latency rised up t0 450-500us at idle, like you.
I don't have any crackling sound but some games are suttering now (dying light, Fallout 4). With the Titan X, they were butter smooth.
I am on Win 7 64 by the way

Hello,
Same boat here,
I come from a titan X and my latency was 20-25us before (at idle). The only thing i changed in my system is my new GTX 1080 (MSI gaming) as i was already using the last drivers and now my latency rised up t0 450-500us at idle, like you.
I don't have any crackling sound but some games are suttering now (dying light, Fallout 4). With the Titan X, they were butter smooth.

[quote="Psiboy"]Maybe it's a windows 7 driver issue?[/quote]
I wish it'd be that, but I created a dual boot on my computer and installed windows 10. I installed nothing but the nvidia driver and latency mon to check out if the issue would go away. And unfortunately, this wasn't a success. DPC was all over the place even on windows 10 :(

I wish it'd be that, but I created a dual boot on my computer and installed windows 10. I installed nothing but the nvidia driver and latency mon to check out if the issue would go away. And unfortunately, this wasn't a success. DPC was all over the place even on windows 10 :(

[quote="Birdy62"]Hello,
Same boat here,
I come from a titan X and my latency was 20-25us before (at idle). The only thing i changed in my system is my new GTX 1080 (MSI gaming) as i was already using the last drivers and now my latency rised up t0 450-500us at idle, like you.
I don't have any crackling sound but some games are suttering now (dying light, Fallout 4). With the Titan X, they were butter smooth.
I am on Win 7 64 by the way[/quote]
If I set the power management mode to maximum performance, the crackling sound goes away and the stuttering lessen a bit, but nothing magical I am afraid. Anyway, thanks for reporting this :)!

Birdy62 said:Hello,
Same boat here,
I come from a titan X and my latency was 20-25us before (at idle). The only thing i changed in my system is my new GTX 1080 (MSI gaming) as i was already using the last drivers and now my latency rised up t0 450-500us at idle, like you.
I don't have any crackling sound but some games are suttering now (dying light, Fallout 4). With the Titan X, they were butter smooth.

I am on Win 7 64 by the way

If I set the power management mode to maximum performance, the crackling sound goes away and the stuttering lessen a bit, but nothing magical I am afraid. Anyway, thanks for reporting this :)!

[quote="Psiboy"]My DPC is like 500-700 higher if the card is at idle clocks or full load. If it's high clocks and low load
like 10-60% the latency is below 50 (like it was before with my 670). Playing Witcher 3 spikes I have above 1000us which is not good.[/quote]
Thanks for reporting this too! :)

Psiboy said:My DPC is like 500-700 higher if the card is at idle clocks or full load. If it's high clocks and low load
like 10-60% the latency is below 50 (like it was before with my 670). Playing Witcher 3 spikes I have above 1000us which is not good.

[quote="Sora"]try configuring the system so the nvidia driver is using MSI's nstead of IRQ's.
http://www.mediafire.com/download/hrxw4rsb9xnw1ei/MSI_util.zip
use that utility.[/quote]
Already tried this with no change.

[quote="Psiboy"][quote="Sora"]try configuring the system so the nvidia driver is using MSI's nstead of IRQ's.
http://www.mediafire.com/download/hrxw4rsb9xnw1ei/MSI_util.zip
use that utility.[/quote]
Already tried this with no change.[/quote]
Same here :(

Still there, still annoying. If you are reading this test it yourself. Use a program that checks for DPC latency and then run Heaven Benchmark maxed out and windowed. See if you latency spikes, then grab (click) and hold the Heaven window which will freeze the benchmark and the latency should go down. Here's an image of mine. Where the green bars are high is when Heaven was running and then when I click and hold the window to stop the rendering they drop.
[url]http://imgur.com/JogGcqv[/url]

Still there, still annoying. If you are reading this test it yourself. Use a program that checks for DPC latency and then run Heaven Benchmark maxed out and windowed. See if you latency spikes, then grab (click) and hold the Heaven window which will freeze the benchmark and the latency should go down. Here's an image of mine. Where the green bars are high is when Heaven was running and then when I click and hold the window to stop the rendering they drop.